One reason I sent Waco some 31-165c slick side FP GC I push hard in the 308w. The BC isn't for long range .
One reason I sent Waco some 31-165c slick side FP GC I push hard in the 308w. The BC isn't for long range .
LOL!!!!! I'm not going here again!!!! I know you were a big part of the design of the 30 xcb mold. You have told people for a LONG time that you can not get accurate (sub 2 MOA) loads with a fast 10 twist barrel at distance with high velocity.
500 yards. 2600+fps. Sub 2 MOA accuracy. Video proof. I don't care ONE BIT what you can do with 1:14-1:16 twist.
My point is you CAN do it with a 10 twist. No RPM threshold. At least I have not hit it yet.
Stellar groups and results Larry at 600 yards with your 1:16 twist custom rifles. I commend you. Well done Sir. I take nothing away from you.
I'm just showing everyone it can be done with a bone stock 10 twist at 2600+fps as well.
Happy shooting my friend.
Walter
waco
Perhaps you failed to notice my post was addressed to megasupermagnum. My post addressed the points/questions he raised. Whether or not you care "ONE BIT" or not is not relevant to my response to him. However, you certainly are entitled to your own opinion, just no need to denigrate someone else to make your point.
You are also still wrong. I have consistently told everyone for numerous years on this forum how to push the RPM Threshold up. The RPM Threshold is not a "limit" but can be moved up or down by using different components and bullet designs. On your previous 500 yard thread(s) I again explained how. The loads you used on those threads did, in fact, hit the RPM Threshold. That's why the load used then gave 4 - 5 moa. In this test you changed to a different, slower burning powder than previously used with a slower time/pressure curve which, just as I've consistently said to do, is a change of components. You also changed to an alloy closer to what has proven to be best at HV. Doing such it appears you have met with success with the load and components used in this thread. It indeed appears you have pushed the RPM Threshold up quite a bit in your 308W with 10" twist barrel, well done. In the previous post my only mention of you and your shooting in this thread was a compliment on how you are demonstrating how the RPM Threshold can be pushed up.
As to the information I posted to megasupermagnum, it applies to the bullet designs he mentioned, particularly the 311466 Loverin design in a 10" twist barrel and also in other twists. Those are not the NOE 30XCB you used. My explanation to him was to lend back ground information to the suggestions for his 200 gr bullet design and his questions regarding the 311466 Loverin design.
Question for you; do you think my milsurp F.M.A.P. M98 action with a Midway special $89.95 24" sporter contour Adams & Benet barrel in a sporter wood stock is the equal of your "bone stock" M700 heavy barrel rifle?
Great job to both you and your brother Waco.
I like the way you setup your cameras in the video..
Other than my 7.62X39 I haven't shot cast or casted bullets for the last few years..
Fact is have shot very little the last two years due to back and joint problems, but things are getting better on that score..
Your thread here and vid. have shown myself and others that we don't don't need a 1:16/26" barreled custom wildcat chambered rifle to shoot @ 2500fps+..
As I don't own the 30 XCB mold I have a few questions before I consider ordering one..
1. How far off the lands are you with that bullet?
2. What is your COAL?
3. Does that bullet feed from both sides of the magazine?
4. Can you keep the bullet base in the neck of your .308?
That is all I can think of for now as you covered most all the bases with your reloading data..
Looking forward to you or your brother wacking a Muley buck this season as I am wondering how that bullet and alloy will act on game at high velocity..
TIA for your reply..
Heck, 2500+ fps out of any 308W rifle with a cast bullet is very easy........ the hard part is hitting something at any real distance........ it appears waco is succeeding.......anyone else?
Waco, outstanding! Great video, and thanks for posting!
That goes without saying, that's why I didn't bring it up...[smilie=l:Quote:
Originally Posted by Larry Gibson
Loved the videoQuote:
Originally Posted by waco
Really enjoyed it
Hate the RPM non-sense
Whether or not there is a quantifiable "RPM threshold", surely there is a point at which a cast bullet cannot grip the rifling any more. I want to give higher velocity cast a try in rifles, for no other reason than to just find out what happens. I've got a handful of 30 caliber molds, and haven't tried really pushing any of them. If I were to buy a mold, why would the 30 XCB be a good choice, rather than some others? My own thinking with a 200 grain bullet, is that 2500 fps is REALLY pushing it with 308 winchester. Maybe higher pressure would be a better way to say it. With 200 grain you get a more manageable velocity range to work with , more bearing surface, and more thump down range. It should have a higher ballistic coefficient too. There's nothing wrong with the 170 grain at 1800 fps I've been shooting, but 200 grains at 2400 fps sounds like a lot of fun for shooting steel. I looked into paper patching, special alloys, etc. If I can't do it with a heat treated cast bullet, I loose interest. I've got a 308 Winchester 1:10" twist, may put a 308 1:12 twist barrel on my savage 110. My barrel has a generous throat. I have not measured it, but I can seat bullets out a long ways. Anyway, the bullet below is what I had in mind. It is calculated as 200 grains, and the gas check would probably be below the neck. What's so bad about the gas check below the neck?
Attachment 230394
Depends. Is it a 1:10 twist? It's also a longer barrel than my 700Quote:
Originally Posted by Larry Gibson
The alloy used is the same as last time.
And you should look at a burn rate chart. H414 is faster than IMR 4831.
1. bullet touching lands.Quote:
Originally Posted by Nrut
2. 2.750"
3. I single load the rifle
4. quite easily.
megasupermagnum
"....surely there is a point at which a cast bullet cannot grip the rifling any more."
The cast bullet not gripping the rifling is not the reason for the loss of accuracy. The RPM Threshold is when the centrifugal force acting upon the imbalances causes the bullet to begin an ever increasing helical spiral or to go off on a tangent to the intended line of flight. The bullets do not become unstable as they would if they "stripped in the rifling".
Good job Waco, love watching your videos!
I've been reading your posts for months, if not years. You just confused me good. So why wouldn't a proper fitting bore rider work just as well for higher velocity use? This is assuming the nose is slightly engraving, bullet seated so the front band lightly jams in the rifling, and otherwise is a well cast and sized bullet.Quote:
Originally Posted by Larry Gibson
Yes the twist is 10", it's the same rifle you asked me to shoot at 500 yards in your previous threads. As per my question the barrel is a "Midway special $89.95 24" sporter contour Adams & Benet" which is 2" longer than your M700 barrel. Let me clarify the question as I was referencing your "bone stock" description of your rifle. Do you think/consider my put together rifle (by me, no custom work done....even has the milsurp trigger) using an Argentine made M98 action, the A & B barrel and an old sporter contour stock has any advantage over your "bone stock" non sporter M700 Remington? If you think it has an advantage what might that advantage be?Quote:
Originally Posted by waco
Yes H414 is listed in the charts as slightly faster burning than IMR4831 and it is probably most often with jacketed bullets. However with cast bullets I found in testing it in the .308W using the 30 XCB bullet and measuring the pressures H414 gives have a bit slower time/pressure curve than even IMR 4831 and H4831. That means with that cast bullet it is slower burning than the 4831s. I think that has to do with the ball vs stick shape of the powder and the different deterrents method of controlling the burn used on ball powder. The burn rate charts are guides, they are not written in stone.
Interesting. I was looking at NOE's site and they show "how to seat" this boolit and it has the GC in past the neck and a COL of 2.629". I have a different mold that is the 311-174-FN-AQ5 and I size to .311. I've only made dummy boolits so far to test the fit/function in my rifle and I found that if I seat it at a COL of 2.7" then about 0.07" of the boolit is past the neck and the boolit is about 0.005-0.01" from touching the lands - too close to measure with my calipers. But this is how NOE shows how to seat the 30 CXB...Quote:
Originally Posted by waco
These things are interesting... A little bit here and there makes things work or NOT work. I cannot wait to load and shoot my boolits.
Thanks again for the inspiration!
Attachment 230401
http://noebulletmolds.com/NV/product...roducts_id=915
44Blam. Glad I could help.
Yes H414 is listed in the charts as slightly faster burning than IMR4831 and it is probably most often with jacketed bullets. However with cast bullets I found in testing it in the .308W using the 30 XCB bullet and measuring the pressures H414 gives have a bit slower time/pressure curve than even IMR 4831 and H4831
You really expect anyone to believe that a rifle can tell the difference between cast and jacketed Bullets to alter the burn rate of a given powder?
The only thing that would make any significance difference is if the bullet has any jump to the lands or is jammed. A cast bullet will have less drag going down the barrel than a jacketed bullet creating less pressure. Not sure where you come up with this?
waco
I never said the burning rate was "altered". What I said was the time/pressure curves are slower indicating the H414 powder was burning slower than the 4831s under the 30 XCB in the 308W cartridge. Had nothing to do with the rifle to "alter" the burn rate. I have measured the time/pressure curves....that's a fact.
And, yes, I do "expect" a lot of intelligent people who do not let their own personal feels alter their perspective to believe it. Here is just a couple of explanations (there are many more if you'd bother to look);
Why Powder Burn Rate Is Meaningless
By Randy Wakeman
Perhaps you have looked at various "Burn Rate Charts" and wondered what good they are. Well, you have good reason to wonder. Burn rate charts seldom agree. There is no specific meaning for "burn rate," so it shouldn't surprise us that the numbers don't agree. They mean nothing by themselves.
What amateurs call burn rate is not used by professional ballisticians to develop loads. The actual term closest to burn rate used in interior ballistics is "Relative Quickness."
Relative quickness is defined by "closed bomb tests," which quantify pressure rise in a sealed container. However, professional ballisticians do not use relative quickness for load development, either. A closed bomb relative quickness value does not translate into any type of value outside of that 'closed bomb' test. Powder performance varies widely by actual application. Relative quickness is one of several preliminary considerations when assessing a powder's suitability for a particular application by ballistics, but nothing more than that.
Relative quickness does not tell use the physical shape of a powder, its composition, or the types of coatings. It cannot tell us whether a powder is single-based, double based, or triple based. It does not tell us the heat of explosion, the progressive / degressive gas creation values, the ignition characteristics, and so forth. There is no way to translate a double-based powder performance into a single-based powder performance level with any accuracy. Even further, relative quickness does not define the erosiveness of a powder, the residue left by a powder, its ability to meter properly; and on it goes.
Energy content of nitrocellulose varies by manufacturer. It varies by the amount of nitrogen in the nitrocellulose. The more nitrogen, the more gas a powder can make. Once you have a specific type of nitrocellulose the energy content is further controlled by the addition of nitroglycerin, which is basically what constitutes a double-based powder. Now you have further considerations, as nitrocellulose and nitroglycerin do not behave the same way as temperature changes. The amount of nitro percentage varies by powder to powder, and with it its performance in a specific application.
All this combines to make burn rate charts something to ignore, or to view with very little importance placed on them. Professional ballisticians do not use them at all, simply because they have no particular meaning. Ping-Pong balls are nitrocellulose, but not many of us would bother cutting them up and attempting to use them in a firearm.
From Sierra’s Exterior Ballistics;
The following powders are listed by their approximate burning rate, from “fastest” to “slowest.” It must be clearly understood that burning rates are not linear. There may be several powders which have very nearly the “same” relative quickness listed together, with the next listed powder being significantly different. It should also be understood that the burning rate of any given powder can vary substantially when different cartridges are being compared. Smokeless propellants are organic compounds, and are subject to lot-to-lot variations that are unavoidable during the manufacturing process. As a result, it is quite possible for a “fast” lot of a “slower” burning powder to appear to be somewhat “faster” than a “slow” lot of what would normally be thought of as a faster burning propellant. This these listings are subject to change depending on the particular lots of powder involved and a host of other variables that become part of the equation.situation, in effect, would cause these two powders to switch positions in the following chart. Bear in mind then, that In the following chart, the column on the left lists the powder manufacturer along with their full designation for the powder in question.
Perfect..Quote:
Originally Posted by waco
Will be ordering one of these molds next month, Merry Christmas to me, lol..
And thanks for your reply..